On Mon, Apr 20, 2020 at 2:29 PM Владимир Калачихин <
address@hidden> wrote:
\20.04.2020 18:08, Lucien Van Elsen пишет:
> You should not assume 'under way using engine' means 'must be moving',
> which seems to be the underlying misunderstanding here.
Not this. As You say - "to do some sanity checking of its own". In the
subject of the sentences almost whole parms are undefined. But not
"status"? This strange.
Ultimately, it is up to the AIS transponder to determine what fields to set; gpsd is just accurately reporting what it received. In the case of a ship that is not moving (speed 0), course over ground does not have any meaning. Additionally, AIS transponders on smaller vessels may not have any way to independently determine the heading without a course - and will then report it as not available. In one of the common themes with gps receivers - many manufacturers do unexpected things, especially in places where the protocol specification is vague. Your software will need to be robust in regards to odd inputs. Gpsd is just the messenger passing along in the data, in this case.